The only way it's remotely doable in less than 20 minutes is with 4 stealthers.
A decent group takes about 22-25 minutes.. Try to actually time it from the time it pops, untill you're actually through it.
And for the OP, if you don't enjoy it, don't play it.. And it's just plain stupid to say LI HM is harder than EC SM..
It also kinda sounds like you don't know you can cleanse the dot on the last fight in there.. When I'm there as a healer I click through everyone now and then and cleanse the dot.. I'm pretty sure I can do that flashpoint without a tank even.
Thats what i mean about class composition.